Prevention and Control of Diseases and pests of traditional Chinese Medicine Ginseng

Disease

Blight disease: Rhizoetonia solani kuhn. The pathogen is a kind of half-known bacteria in fungi. Also known as "soil choking disease". The disease mainly occurs in the stage of seedling emergence and leaf expansion. The disease of 1-year-old ginseng was serious, the stem of the injured ginseng seedlings showed brown ring constriction at the junction of dry and wet soil under the soil surface, and the seedlings collapsed and died.

Prevention and control methods: before sowing, 50% carbendazim per mu was used to treat the soil; 50% carbendazim was used to irrigate the disease area with 1000 times of carbendazim at the initial stage of the disease, and the depth was about 4~5cm. After irrigation, ginseng leaves were washed with clean water; disinfection treatments such as disinfection with 5% lime milk were used to find diseased plants; field management was strengthened to keep the seedbed ventilated to avoid excessive soil moisture.

Bacterial soft rot: mainly harms the roots. The disease spot is brown soft rot, the edge is clear, round to irregular shape, different size, constant combination, and finally lead to the whole ginseng root soft rot. Squeeze the disease spot with the hand, there is a white bacterial pus overflow, with a strong irritating smell. When the disease is serious, the whole ginseng root tissue decays and disintegrates. At the initial stage of the aboveground part of the plant, the edge of the leaf turned yellow and curled up slightly, and irregular brown or red spots appeared on the leaf. In severe cases, the whole leaves showed purplish red, and finally the leaves wilted. Wilting developed from recoverability to non-recoverability.

Pathogen: there are two kinds of bacteria: (1) Pseudomonas caryophyllus Pseudomonas caryophylli Starr et Burkholder, which belongs to Pseudomonas aeruginosa. The cell was rod-shaped, without capsule, polar flagellum and negative for Gram staining. (2) the variety Erwinia carotovoravar of carrot soft rot. Carotovora Bya., belongs to Euclidean bacteria. The mycelium was short rod-shaped, with weekly flagella and negative Gram staining.

Disease regularity: ginseng soft rot bacteria exist in a large number of soil, and the soil is the overwintering place and primary infection source of soft rot bacteria. Bacteria invade ginseng root mainly through wound. When the ginseng root has strong growth and strong disease resistance, the pathogen is in a latent state. All parts of ginseng root can become the latent place of soft rot bacteria, especially the spore carrying rate is the highest. When the growth of ginseng root is weak, the disease resistance is reduced, or the external temperature and humidity conditions are suitable, the ginseng root appears soft rot symptoms. In the later stage of the disease, it is often co-infected with Fusarium, Rhizoctonia and other fungi, and the mycelium of fungi appear on the outside of the lesion.

Prevention and control measures: (1) choose high-dry land to plant ginseng to prevent soil consolidation and stagnant water; do not use planting with wounds, and prevent ginseng root injury when transplanting. (2) strengthen cultivation and management, protect against cold in time in winter, and pay attention to the control of underground pests in order to reduce wounds. (3) soil disinfection: 20% copper acetate wettable powder 50 g / curtain mixed, 80% allicin EC 1000 × 2000 times spray, 50% chlorobromoisocyanuric acid water soluble powder 1000 times, etc.

Spot disease (black spot): Alternaria panax whetz. The pathogen is a kind of half-known bacteria in fungi, and the disease is mainly harmful to leaves. Stems and fruits are also damaged when they are ripe. It began to occur in the middle of June, and the peak period was from July to August. The disease spot of the leaf is round or irregular waterlogged at first, then gradually enlarged, yellowish brown, wavy wheel, easy to break. Dark brown spots appeared on the injured stems and pedicels. When the air humidity is high, especially in the rainy season, the disease occurs and spreads rapidly, and when it is serious, the plant wilts and dies in the early stage.

Prevention and control methods: timely curtain, flower arrangement and rain prevention, do a good job of border surface and operation road cleaning and hygiene; spray control with 5% Tian'an water agent 400 times before or when the disease occurs; 1 120 times Bordeaux solution; 65% wettable mansen zinc 500 times solution; 50% wettable carbendazim 600 times 800 times liquid or 50% wettable carbendazim 600 times liquid and so on.

Epidemic disease: Phytophthora cactorum leb.et cohnsehrot. Also known as "pull hand towel". The pathogen is a kind of algal bacteria in fungi. It occurs during the rainy season from July to August. Mainly damage leaves, stems and roots can also be damaged. The disease was especially serious in plants over four years. The disease spot on the leaves is water-stained, dark green, and develops rapidly. once infected, the leaves of the whole plant wither and droop, like hot water, hence the name. The root is infected with yellowish brown soft rot, the root bark is easy to peel off, and the internal tissue shows a yellowish brown irregular pattern with fishy smell. After the disease, the outer skin often has white hyphae and agglutinated soil particles. It is easy to get sick when it rains continuously in summer and the humidity is high.

Prevention and treatment methods: keep the ginseng border in good ventilation and drainage conditions, close the curtain and arrange flowers in time to prevent the invasion of Rain Water; apply more phosphorus and potassium fertilizer to improve disease resistance; immediately remove and burn the diseased plants, and disinfect the diseased points with 5% lime milk; spray with 11DZ 120 Bordeaux solution or 65% Dysen zinc 500x solution before onset; Dixone 500x solution, once every 10 days, 2 times in a row.

Rust rot: Ramularia panacicola zinss. Pathogen is a kind of half-known bacteria in fungi. It can occur all the year round, and the peak period is from June to July. Plants can be infected from seedling to mature stage. The root, Reed head and overwintering bud were mainly damaged, and the disease showed yellowish brown dry rot. After the root and Reed head were killed, the disease spot initially became yellowish brown, gradually expanded and spread to the internal tissue, and small soft particles appeared in the disease part, resulting in the rupture of the epidermis, and after scraping off the decaying material, there was a concave mark, and there was a clear boundary between the disease part and the healthy tissue. But bacteria often invade from the disease wound, accelerate the rotting root, and finally rot off all the ginseng root or Reed head. After the root and Reed head were infected, the aboveground parts did not change at first, but in the later stage, red or yellowish brown disease spots appeared on the leaves, and finally the whole leaves turned red and withered and died. After the overwintering buds are damaged, they become yellowish brown and often rot in the ground and cannot grow from stems. The disease is serious when the soil is heavy, the water content is high and the ventilation is poor.

Prevention and treatment methods: strictly select disease-free ginseng seedlings, fully plough the ginseng ground, loosen the soil and close the curtain to prevent excessive soil moisture; when the disease is serious, dig up ginseng plants in autumn, soak the roots with 1purl 100 times Bordeaux solution or 65% wettable zinc 100 times solution without soaking buds for 10 minutes, and plant them in disease-free land.

Sclerotinia disease: Sclerotinia SP. The pathogen is an ascomycete in fungi. The bacteria occurred from May to June and spread after autumn. Mainly against more than four-year-old ginseng root, bud, Reed head can also be killed. At the beginning of the disease, the appearance of the root was normal, but the internal tissue was soft, the finger pressure was fragile, and then it gradually showed gray-black soft rot, white hyphae grew in the injured part, and only skin and fiber tissue were left in the root in the later stage, and finally black mouse dung-like sclerotia was formed in the root bark, causing the root to rot. The aboveground stems and leaves of the diseased plants shrunk slightly in the early stage and withered and died in the later stage. When the temperature is low, the humidity is high and the soil permeability is poor in spring and autumn, it is easy to spread.